1. Field
The present invention relates generally to electronic circuits and communication apparatus. More particularly, in aspects the invention relates to latches, frequency dividers, synthesizers, and wireless communication devices employing such devices.
2. Background
Frequency dividers are used in various electronic devices, including portable wireless devices such as cellular telephones and personal digital assistants. Output waveforms of a frequency divider are typically derived from either the rising edges or the falling edges of the divider's input. For this reason, odd number dividers (e.g., divide by 3, 5, 7, etc.) have outputs that are commonly restricted to pulse widths that are integer multiples of the period of their inputs. Since a full output cycle of an odd number frequency divider is equal to an odd number of its input cycle duration, getting a fifty percent duty cycle generally requires pulse widths that correspond to a non-integer number of input cycles. This may unnecessarily restrict the frequency choices available to designers of the equipment using the odd number dividers.
A need thus exists for frequency dividers, frequency divider components such as latches, and methods for operating frequency dividers that overcome the above-described limitation of existing circuits and do not unduly restrict the choice of operating frequency when dividing by an odd number. A further need exists for communication apparatus, including wireless communication apparatus, with such dividers.